Having a hard time re-installing GIMP

So I had an earlier version of GIMP, but somehow ended up with multiple instances of most files. It was taking up WAAAAY too much space, and was slow to start, so I tried deleting the program, then reinstalling. However, if GIMP has an uninstall tool, I didn't think to use it, and now I can't get the new GIMP to install. I keep getting an alert after everything is unpacked that a specific registry error is occurring, specifically: